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EC number: 246-045-1 | CAS number: 24157-81-1
- Life Cycle description
- Uses advised against
- Endpoint summary
- Appearance / physical state / colour
- Melting point / freezing point
- Boiling point
- Density
- Particle size distribution (Granulometry)
- Vapour pressure
- Partition coefficient
- Water solubility
- Solubility in organic solvents / fat solubility
- Surface tension
- Flash point
- Auto flammability
- Flammability
- Explosiveness
- Oxidising properties
- Oxidation reduction potential
- Stability in organic solvents and identity of relevant degradation products
- Storage stability and reactivity towards container material
- Stability: thermal, sunlight, metals
- pH
- Dissociation constant
- Viscosity
- Additional physico-chemical information
- Additional physico-chemical properties of nanomaterials
- Nanomaterial agglomeration / aggregation
- Nanomaterial crystalline phase
- Nanomaterial crystallite and grain size
- Nanomaterial aspect ratio / shape
- Nanomaterial specific surface area
- Nanomaterial Zeta potential
- Nanomaterial surface chemistry
- Nanomaterial dustiness
- Nanomaterial porosity
- Nanomaterial pour density
- Nanomaterial photocatalytic activity
- Nanomaterial radical formation potential
- Nanomaterial catalytic activity
- Endpoint summary
- Stability
- Biodegradation
- Bioaccumulation
- Transport and distribution
- Environmental data
- Additional information on environmental fate and behaviour
- Ecotoxicological Summary
- Aquatic toxicity
- Endpoint summary
- Short-term toxicity to fish
- Long-term toxicity to fish
- Short-term toxicity to aquatic invertebrates
- Long-term toxicity to aquatic invertebrates
- Toxicity to aquatic algae and cyanobacteria
- Toxicity to aquatic plants other than algae
- Toxicity to microorganisms
- Endocrine disrupter testing in aquatic vertebrates – in vivo
- Toxicity to other aquatic organisms
- Sediment toxicity
- Terrestrial toxicity
- Biological effects monitoring
- Biotransformation and kinetics
- Additional ecotoxological information
- Toxicological Summary
- Toxicokinetics, metabolism and distribution
- Acute Toxicity
- Irritation / corrosion
- Sensitisation
- Repeated dose toxicity
- Genetic toxicity
- Carcinogenicity
- Toxicity to reproduction
- Specific investigations
- Exposure related observations in humans
- Toxic effects on livestock and pets
- Additional toxicological data
Endpoint summary
Administrative data
Key value for chemical safety assessment
Genetic toxicity in vitro
Description of key information
Gene mutation in bacteria in vitro (similar OECD 471): negative in S. typhimurium TA 98, TA 100, TA 1535, TA 1537 and E. coli WP2 uvr A with and without metabolic activation
Study performed with 2,6-diisopropylnaphthalene (CAS No. 24157-81-1)
Chromosome aberration study in mammalian cells in vitro (OECD 473): negative in Chinese Hamster Ovary (CHO) cells with and without metabolic activation
Read-across from analogue source substance bis(isopropyl)naphthalene (CAS No. 38640-62-9)
Gene mutation study in mammalian cells in vitro (OECD 476): negative in mouse lymphoma L5178Y cells with and without metabolic activation
Read-across from analogue source substance bis(isopropyl)naphthalene (CAS No. 38640-62-9)
Link to relevant study records
- Endpoint:
- in vitro gene mutation study in bacteria
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Study period:
- 25 Sep - 04 Nov 1997
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- guideline study
- Qualifier:
- according to guideline
- Guideline:
- EPA OPP 84-2
- Qualifier:
- equivalent or similar to guideline
- Guideline:
- OECD Guideline 471 (Bacterial Reverse Mutation Assay)
- GLP compliance:
- yes
- Type of assay:
- bacterial reverse mutation assay
- Target gene:
- his operon for S. typhimurium strains and trp operon for E. coli strain
- Species / strain / cell type:
- S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
- Species / strain / cell type:
- E. coli WP2 uvr A
- Metabolic activation:
- with and without
- Metabolic activation system:
- Type and composition of metabolic activation system:
Cofactor supplemented post-mitochondrial fraction (S9 mix), prepared from the livers of male Sprague-Dawley rats treated with 500 mg/kg bw Aroclor 1254.
- source of S9 : Molecular Toxicology, Inc., USA, Batch 0745 (33.15 mg of protein per mL) and Batch 0781 (40.7 mg of protein per mL)
- quality controls of S9 (e.g., enzymatic activity, sterility, metabolic capability): yes - Test concentrations with justification for top dose:
- First and second experiment: 100, 250, 500, 1000, 2500, 5000 µg/plate, with and without metabolic activation
Dose levels selected based on a dose range finding study - Vehicle / solvent:
- - Vehicle: Dimethylformamide (DMF)
- Source: Sigma Chemical Co., USA (Lot 125H3633, Lot 37H3649, and Lot 47H3674)
- Justification for choice of solvent/vehicle: The solvent was chosen due to the limited solubility of the test substance - Untreated negative controls:
- no
- Negative solvent / vehicle controls:
- yes
- True negative controls:
- no
- Positive controls:
- yes
- Positive control substance:
- 4-nitroquinoline-N-oxide
- 2-nitrofluorene
- sodium azide
- other: 2-aminoanthracene, 2.5 µg/plate for S. typhimurium strains, 25 µg/plate for E. coli strain, +S9
- Details on test system and experimental conditions:
- NUMBER OF REPLICATIONS:
- Number of cultures per concentration: triplicate
- Number of independent experiments . 2
METHOD OF TREATMENT/ EXPOSURE:
- Test substance added in agar (plate incorporation)
- Exposure duration and conditions: 48 ± 8 h at 37 ± 2 °C
METHODS FOR MEASUREMENT OF CYTOTOXICITY
- Method: Inspection of the bacterial background lawn
METHODS FOR MEASUREMENTS OF GENOTOXICIY
Counting of revertant colonies - Evaluation criteria:
- The test material may be considered positive in this test system if the following criteria are met: For the test item to be considered mutagenic, two-fold (three-fold for TA 1535 and TA 1537) increases in mean revertant numbers must be observed. In addition, there must be evidence of a dose-response relationship showing increasing numbers of mutant colonies with increasing dose levels. All cultures must demonstrate the characteristic mean number of spontaneous revertants in the vehicle controls.
- Statistics:
- Mean values and standard deviation were calculated.
- Key result
- Species / strain:
- S. typhimurium TA 1535
- Metabolic activation:
- with and without
- Genotoxicity:
- negative
- Cytotoxicity / choice of top concentrations:
- no cytotoxicity, but tested up to precipitating concentrations
- Remarks:
- precipitation at and above 1000 µg/plate
- Vehicle controls validity:
- valid
- Untreated negative controls validity:
- not examined
- True negative controls validity:
- not examined
- Positive controls validity:
- valid
- Key result
- Species / strain:
- S. typhimurium TA 1537
- Metabolic activation:
- with and without
- Genotoxicity:
- negative
- Cytotoxicity / choice of top concentrations:
- no cytotoxicity, but tested up to precipitating concentrations
- Remarks:
- precipitation at and above 1000 µg/plate
- Vehicle controls validity:
- valid
- Untreated negative controls validity:
- not examined
- True negative controls validity:
- not examined
- Positive controls validity:
- valid
- Key result
- Species / strain:
- S. typhimurium TA 98
- Metabolic activation:
- with and without
- Genotoxicity:
- negative
- Cytotoxicity / choice of top concentrations:
- no cytotoxicity, but tested up to precipitating concentrations
- Remarks:
- precipitation at and above 1000 µg/plate
- Vehicle controls validity:
- valid
- Untreated negative controls validity:
- not examined
- True negative controls validity:
- not examined
- Positive controls validity:
- valid
- Key result
- Species / strain:
- S. typhimurium TA 100
- Metabolic activation:
- with and without
- Genotoxicity:
- negative
- Cytotoxicity / choice of top concentrations:
- no cytotoxicity, but tested up to precipitating concentrations
- Remarks:
- precipitation at and above 1000 µg/plate
- Vehicle controls validity:
- valid
- Untreated negative controls validity:
- not examined
- True negative controls validity:
- not examined
- Positive controls validity:
- valid
- Key result
- Species / strain:
- E. coli WP2 uvr A
- Metabolic activation:
- with and without
- Genotoxicity:
- negative
- Cytotoxicity / choice of top concentrations:
- no cytotoxicity, but tested up to precipitating concentrations
- Remarks:
- precipitation at and above 1000 µg/plate
- Vehicle controls validity:
- valid
- Untreated negative controls validity:
- not examined
- True negative controls validity:
- not examined
- Positive controls validity:
- valid
- Additional information on results:
- TEST-SPECIFIC CONFOUNDING FACTORS
- Water solubility: The test substance is poorly soluble in aqueous solutions. Therefore, DMF was used as vehicle..
- Precipitation and time of the determination: At a concentration of 1000 µg/mL and above the test material precipitated in the cell culture medium. The precipitation did not interfere with the counting of the colonies.
RANGE-FINDING/SCREENING STUDIES:
In the range finding test, the substance was tested up to 5000 µg/plate in the absence and presence of S9 mix in S. typhimurium TA100 and E. coli WP2uvrA. No reduction of the bacterial lawn and no biologically relevant decrease in the number of revertants were observed. The highest concentration analysed was selected based on the solubility of the test substance in the cell culture medium.
STUDY RESULTS
- Concurrent vehicle negative and positive control data : Refer to pdf document provided under 'Attached background material'. - Conclusions:
- Interpretation of results: negative with and without metabolic activation
- Endpoint:
- in vitro cytogenicity / chromosome aberration study in mammalian cells
- Type of information:
- read-across from supporting substance (structural analogue or surrogate)
- Adequacy of study:
- key study
- Justification for type of information:
- Refer to the analogue approach justification provided in IUCLID section 13
- Reason / purpose for cross-reference:
- read-across source
- Key result
- Species / strain:
- Chinese hamster Ovary (CHO)
- Metabolic activation:
- with and without
- Genotoxicity:
- negative
- Cytotoxicity / choice of top concentrations:
- other: ≥15 µg/ml (without S9); ≥ 60 µg/ml (with S9)
- Vehicle controls validity:
- valid
- Untreated negative controls validity:
- not examined
- Positive controls validity:
- valid
- Conclusions:
- Interpretation of results: negative with and without metabolic activation
- Executive summary:
The potential to induce chromosome aberration in mammalian cells of the target substance is predicted based on an adequate and reliable in vitro study of a structural analogue source substance. Experiments have been performed both in the presence as well as in the absence of metabolic activation in chinese hamster ovary (CHO) cells. All results obtained are negative, i.e. no chromosome aberration in the cells investigated were observed. There was no evidence of any clastogenic activity under the conditions of the test. Therefore, no hazard with regard to chromosome aberration in mammalian cells is identified for the target substance. As explained in the analogue justification, the differences in molecular structure between the target and the source substances are unlikely to lead to differences in the potential to form chromosome aberrations.
- Endpoint:
- in vitro gene mutation study in mammalian cells
- Type of information:
- read-across from supporting substance (structural analogue or surrogate)
- Adequacy of study:
- key study
- Justification for type of information:
- Refer to the analogue approach justification provided in IUCLID section 13
- Reason / purpose for cross-reference:
- read-across source
- Key result
- Species / strain:
- mouse lymphoma L5178Y cells
- Metabolic activation:
- with and without
- Genotoxicity:
- negative
- Cytotoxicity / choice of top concentrations:
- other: >=25 µg/ml (+/-S9): <= 20% relative survival
- Vehicle controls validity:
- valid
- Untreated negative controls validity:
- not examined
- Positive controls validity:
- valid
- Conclusions:
- Interpretation of results: negative with and without metabolic activation
- Executive summary:
The potential of the target substance to induce gene mutation in mammalian cells is predicted based on an adequate and reliable in vitro study of a structural analogue source substance. Experiments using mouse
lymphoma L5178Y cells have been performed both in the presence as well as in the absence of metabolic activation. All results obtained are negative, i.e. no gene mutation was observed. There was no evidence of increases in mutant frequency according to the criteria of the test for all test substance concentrations tested without and with metabolic activation. Therefore, no hazard with regard to gene mutation in mammalian cells is identified for the target substance. As explained in the analogue justification, the differences in molecular structure between the target and the source substances are unlikely to lead to differences in gene mutation in mammalian cells.
Referenceopen allclose all
Detailed result tables, incl. individual plate counts, for the dose range finding experiment and both mutagenicity assays are provided in the pdf document provided under 'Attached background material'. Please note that the registrant is authorised to use the study report for the purpose of the REACH registration despite the 'CONFIDENTIAL' stamp on each page.
Source: CAS No. 38640 -62 -9, Brooker, 1988
Source: CAS No. 38640 -62 -9, Ransome, 1999
Endpoint conclusion
- Endpoint conclusion:
- no adverse effect observed (negative)
Genetic toxicity in vivo
Endpoint conclusion
- Endpoint conclusion:
- no study available
Additional information
Only data on gene mutation in bacteria is available for 2,6-diisopropylnaphthalene (CAS No. 24157-81-1). The genetic toxicity endpoints chromosome aberration and gene mutation in mammalian cells are, therefore, assessed by means of read-across from the analogue source substance bis(isopropyl)naphthalene (CAS No. 38640-62-9).
Gene mutation in bacteria in vitro
The potential of 2,6-diisopropylnaphthalene (CAS No. 24157-81-1) to induce gene mutation in bacteria was tested in a study similar to OECD guideline 471 and observing GLP provisions (Lawlor, 1998). The strains S. typhimurium TA 98, TA 100, TA 1537 and TA 1535 and E. coli WP2 uvr A were tested in two independent experiments according to the plate incorporation procedure in the absence and presence of a metabolic activation system (Aroclor 1254-induced rat liver S9-mix). The experiments were conducted each in 3 replications at concentrations from 100 to 5000 µg/plate. Dimethylformamide (DMF) was used as vehicle. No increase in the number of revertant colonies was noted in any of the bacterial strains, with and without metabolic activation system. No cytotoxicity was observed up to the highest dose tested. The positive and negative controls showed the expected results. Under the conditions of the study, the test substance did not induce mutations in the absence and presence of a metabolic activation system in any of the strains tested.
Chromosome aberration in mammalian cells in vitro
An in vitro mammalian chromosome aberration test was conducted with bis(isopropyl)naphthalene (CAS No. 38640-62-9) in accordance with OECD guideline 473 under GLP conditions (Brooker, 1988). The induction of structural chromosome aberrations was evaluated in vitro in Chinese Hamster Ovary (CHO) cells, incubated for 4 h with and for 20 h without a metabolic activation system (S9-mix from rats treated with Aroclor 1245). In a first main test concentrations of 7.5 - 75 µg/mL without S9 mix were applied. This test was dismissed and not continued for chromosomal analysis due to an unexpected reduction in the mitotic index at 75 µg/mL. Therefore, a second main test was initiated with reduced concentrations. In the second main experiment, concentrations of 0.95 - 9.5 µg/mL (4 h incubation) and 6 - 60 µg/mL (20 h incubation) of the test substance in the vehicle DMSO were applied. The negative as well as the positive controls showed the expected results. In the main experiments, a reduction in the mitotic index was observed from 15 µg/mL without and from 60 µg/mL with metabolic activation. No statistically or a biologically significant increase in the incidence of chromosome aberrations was observed. Therefore, under the conditions of the study, the test substance did not show clastogenic activity with and without metabolic activation performed in Chinese Hamster Ovary (CHO) cells in vitro.
Gene mutation in mammalian cells in vitro
The in vitro mammalian cell gene mutation study of bis(isopropyl)naphthalene (CAS No. 38640-62-9) was carried out according to OECD guideline 476 under GLP conditions (Ransome, 1999). Gene mutations in the thymidine kinase locus TK +/- were investigated in mouse lymphoma L5178Y cells in the presence and absence of a metabolic activation system (S9-mix from Aroclor 1254 induced rat liver). L5178Y cells were incubated with the test material at 5 - 40 µg/mL (experiment 1) and 1 - 25 µg/mL (experiment 2) without S9-mix for 3 and 24 h, respectively. In the experiments with metabolic activation, the test substance was incubated at concentrations of 1 - 60 µg/mL (experiment 1) and 1 - 50 µg/mL (experiment 2) for 3 and 24 h, respectively. The vehicle and positive controls in the study showed the expected results. Mean survival (Day 0) in non-selective medium of the solvent control in the absence of S9-mix was 74% and 68%, and in the presence of S9-mix 72 - 88%. In experiment 1 without S9-mix (3 h treatment), a statistically significant increase in mutant frequency (MF) outside the historical control range was observed at the highest dose (40 µg/mL). Mean Day 0 relative survival was 12% and Day 2 cloning efficiency (CE) was 19%. This effect can be explained by the corresponding decrease in Day 2 CE in non-selective medium. No substantial increase was seen in experiment 2 under equivalent conditions. In experiment 1 with S9-mix (3 h treatment), a statistically significant increase in MF outside the historical control range was observed at 20 µg/mL, but not at 50 µg/mL (survival 14%). But this effect was not reproduced in the second test. Colony sizing demonstrated no difference in the ratios small-to-large colonies from the solvent control, while significantly higher yields of small colonies were found in the positive controls. There was no reproducible increase in MF and no evidence of a dose relationship over at least two dose levels. Based on the results of this test, it can be concluded that the test substance did not demonstrate mutagenic potential in the in-vitro mouse lymphoma mutation assay.
Justification for classification or non-classification
The available data on gene mutation in bacteria for 2,6-diisopropylnaphthalene (CAS No. 24157-81-1) as well as the data on chromosome aberration and gene mutation in mammalian cells with the analogue source substance bis(isopropyl)naphthalene (CAS No. 38640-62-9) do not meet the criteria for classification according to Regulation (EC) No. 1272/2008 (CLP). Data are, therefore, conclusive but not sufficient for classification. Based on an analogue read-across approach, the target substance 2,6-diisopropylnaphthalene (CAS No. 24157-81-1) does not warrant classification for genetic toxicity.
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